Package For Combined Steam and Microwave Heating of Food

ABSTRACT

A package for combined steam and microwave heating of food, wherein the package may include microwave energy interactive materials (“MEIMs”) configured for providing rapid, simultaneous microwave and steam cooking in a domestic microwave oven. The MEIMs may be configured for controlling the heating pattern within the package and to control volumetric heating of food in the package. The MEIMs may include one or more of a susceptor, shield, and/or resonating patch antenna. The package may be paper-based, or it may be manufactured of any other suitable material. One or more of the different sections of the package may comprise separate chambers respectively for the steam source and the food to be steamed, so that the steam source and the food to be steamed are separated from one another during manufacturing, storage, and cooking.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. application Ser. No.14/286,311, which was filed on May 23, 2014, which claims the benefit ofU.S. Provisional Application No. 61/827,389, which was filed on May 24,2013.

INCORPORATION BY REFERENCE

U.S. patent application Ser. No. 14/286,311, which was filed on May 23,2014, and U.S. Provisional Application No. 61/827,389, which was filedon May 24, 2013, are hereby incorporated by reference for all purposesas if presented herein in their entirety.

FIELD OF THE DISCLOSURE

This disclosure relates to food preparation, and, more specifically, topackages that may be used to prepare foods in a microwave oven.

BACKGROUND OF DISCLOSURE

Microwave ovens commonly are used to cook food in a rapid and effectivemanner. To optimize the cooking performance of microwave ovens, variouspackaging configurations have been developed to block, enhance, direct,and otherwise affect microwave interaction with food.

SUMMARY OF DISCLOSURE

An aspect of this disclosure is the provision of a variety of packagesfor combined steam and microwave heating of food, wherein the packagesmay include microwave energy interactive materials (“MEIMs”) configuredfor providing rapid, simultaneous microwave and steam cooking in adomestic microwave oven. The MEIMs may be configured for controlling theheating pattern within the package and to control volumetric heating offood in the package. The MEIMs may include one or more of a susceptor,shield, and/or resonating patch antenna.

An aspect of this disclosure is the provision of a relativelyinexpensive, multi-sectional, at least partially separable, microwaveenergy-interactive package for coupled (e.g., simultaneous) microwaveand steam cooking of different frozen or chilled foods in a domesticmicrowave oven. The package may be paper-based, or it may bemanufactured of any other suitable material. One or more of thedifferent sections of the package may comprise separate chambersrespectively for the steam source and the food to be steamed, so thatthe steam source and the food to be steamed are separated from oneanother during manufacturing, storage, and cooking. The section of thepackage for at least partially containing the steam source may be anouter container. For example, the outer container may be in the form ofa pressed bowl, folded carton, cylindrical canister, or any othersuitable container. The outer container may include a susceptor and/orresonating patch antenna strategically located to induce rapid evolutionof steam and/or volatile flavor from frozen/chilled water-basedcomponents.

The section of the package for at least partially containing the food tobe steamed may be an inner container, and the inner container may be abasket or an assembly of baskets. For example, a basket may be in theform of a perforated pressed bowl, perforated folded carton, perforatedcylindrical canister, or any other suitable container (e.g., basket).Each inner container or basket may include one or more susceptors at thesurface in contact with the food, for facilitating partialbrowning/frying of the food while it is being steamed. The perforations,or more generally the holes, in the basket may be arranged for allowingpenetration of steam into the basket at the bottom, sidewall, and/ortop, such as through a head-space.

The sections of the package may be contained as one assembly having anaccess opening that may be covered with a paper-based and/or flexiblepolymeric-based lid. The lid may include MEIM in the form of, orotherwise comprising, one or more shields configured for functioning asone or more ameliorators. The partial transmission of the microwaveenergy due to the ameliorator(s) may allow for tempering and thawing offood, and may allow for balancing of the microwave volumetric heatingeffect with the convection-conduction steam heating effect.

In general, one aspect of the disclosure is directed to a package forheating a food product. The package comprising paperboard material and amicrowave energy interactive material. The package comprising a firstcontainer having a first sidewall and a first bottom wall, the firstsidewall and the first bottom wall cooperating to form a first interiorspace. A second container is received in the first interior space. Thesecond container has a second sidewall and a second bottom wall. Thesecond sidewall and the second bottom wall cooperating to form a secondinterior space. The second interior space comprising a portion of thefirst interior space. The second bottom wall is spaced apart from thefirst bottom wall to at least partially define a first compartment belowthe second bottom wall for receiving a first product and a secondcompartment above the second bottom wall for receiving a second product.The second bottom wall has at least one vent opening for allowing steamto pass from the first compartment to the, second compartment.

In another aspect, the disclosure is generally directed to a method offorming a package for heating a food product. The package comprisingpaperboard material and microwave interactive material. The methodcomprising obtaining a first container having a first sidewall and afirst bottom wall. The first sidewall and the first bottom wallcooperate to from a first interior space. The method comprisingobtaining a second container having a second sidewall and a secondbottom wall. The second sidewall and the second bottom wall cooperate toform a second interior space. The method comprise positioning the secondcontainer in the first container so that the second interior spacecomprises a portion of the first interior space, the second bottom wallis spaced apart from the first bottom wall to at least partially definea first compartment below the second bottom wall for receiving a firstproduct and a second compartment above the second bottom wall forreceiving a second product. The second bottom wall has at least one ventopening for allowing steam to pass from the first compartment to thesecond compartment.

In another aspect, the disclosure is generally directed to a package forheating a food product. The package comprising paperboard material and amicrowave energy interactive material. The package comprising a firstcontainer having a first sidewall and a first bottom wall. The firstsidewall and the first bottom wall cooperating to form a first interiorspace. A second container is received in the first interior space. Thesecond container has a second sidewall and a second bottom wall. Thesecond sidewall and the second bottom wall cooperate to form a secondinterior space. The second interior space comprising a portion of thefirst interior space. The second side wall has a bottom portion that isin contact with the first bottom wall and the second bottom wall isspaced above the bottom portion. The second bottom wall is spaced apartfrom the first bottom wall to at least partially define a firstcompartment below the second bottom wall for receiving a first productand a second compartment above the second bottom wall for receiving asecond product. The second bottom wall has at least one vent opening forallowing steam to pass from the first compartment to the secondcompartment.

In another aspect, the disclosure is generally directed to a package forheating a food product. The package comprising paperboard material and amicrowave energy interactive material. The package comprising a firstcontainer having a first sidewall and a first bottom wall. The firstsidewall and the first bottom wall cooperating to form a first interiorspace. A second container is received in the first interior space. Thesecond container having a second sidewall and a second bottom wall. Thesecond sidewall and the second bottom wall cooperating to form a secondinterior space. The second interior space comprising a portion of thefirst interior space. A third container is received in the firstinterior space. The third container has a third sidewall and a thirdbottom wall. The third sidewall and the third bottom wall cooperate toform a third interior space. The third interior space comprising aportion of the first interior space. The second bottom wall is spacedapart from the first bottom wall to at least partially define a firstcompartment below the second bottom wall for receiving a first productand a second compartment above the second bottom wall for receiving asecond product. The third bottom wall is spaced apart from the secondbottom wall to at least partially define a third compartment above thethird bottom wall for receiving a third product. The second bottom wallhas at least one vent opening for allowing steam to pass from the firstcompartment to the second compartment and the third bottom wall has atleast one vent opening for allowing steam to pass from the secondcompartment to the third compartment.

In another aspect, the disclosure is generally directed to a package forheating a food product. The package comprising paperboard material and amicrowave energy interactive material. The package comprising a firstcontainer having a first sidewall and a first bottom wall. The firstsidewall and the first bottom wall cooperating to form a first interiorspace. The first bottom wall comprising a first support on the firstbottom wall. A second container is received in the first interior space.The second container has a second sidewall and a second bottom wall. Thesecond sidewall and the second bottom wall cooperate to form a secondinterior space. The second interior space comprising a portion of thefirst interior space. The second side wall has a bottom portion that isin contact with the first support and the second bottom wall is spacedabove the bottom portion. The second bottom wall is spaced apart fromthe first bottom wall to at least partially define a first compartmentbelow the second bottom wall for receiving a first product and a secondcompartment above the second bottom wall for receiving a second product.The second bottom wall having at least one vent opening for allowingsteam to pass from the first compartment to the second compartment.

In another aspect, the disclosure is generally directed to a method ofheating a food product in a package in a microwave oven. The methodcomprising obtaining a first container having a first sidewall and afirst bottom wall. The first sidewall and the first bottom wallcooperating to form a first interior space. The method comprisesobtaining a second container having a second sidewall and a secondbottom wall. The second sidewall and the second bottom wall cooperatingto form a second interior space. The second bottom wall having at leastone vent opening. The method comprises positioning the second containerin the first interior space so that the second interior space comprisesa portion of the first interior space and the second bottom wall isspaced apart from the first bottom wall to form a first compartmentbelow the second bottom wall and a second compartment above the secondbottom wall. The method comprises placing a source of steam in the firstcompartment so that the source of steam is supported by the first bottomwall, placing a food product in the second compartment so that the foodproduct is supported by the second bottom wall, and heating the packagein a microwave oven so that steam is created in the first compartmentand circulates to the second compartment through the vent openings inthe second bottom wall so that the food product is heated by the steamand microwave energy.

The foregoing presents a simplified summary of some aspects of thisdisclosure in order to provide a basic understanding. The foregoingsummary is not an extensive summary of the disclosure and is notintended to identify key or critical elements of the disclosure or todelineate the scope of the disclosure. The purpose of the foregoingsummary is to present some concepts of this disclosure in a simplifiedform as a prelude to the more detailed description that is presentedlater. For example, other aspects will become apparent from thefollowing.

BRIEF DESCRIPTION OF THE DRAWINGS

Having described some aspects of this disclosure in general terms,reference will now be made to the accompanying drawings, which are notnecessarily drawn to scale. The drawings are exemplary only, and shouldnot be construed as limiting the disclosure.

FIG. 1 is a perspective view of a package in a fully assembled, closedconfiguration, in accordance with a first embodiment of this disclosure.

FIG. 1A is a cross-sectional view of the package of FIG. 1.

FIG. 2 is an exploded view of the package of FIG. 1.

FIG. 3 is a perspective view of a first container of the package of FIG.1

FIG. 4 is a perspective view of a second container of the package ofFIG. 1.

FIG. 5 is a schematic, side elevation view of the second container ofFIG. 4.

FIG. 6 is a perspective view of a cover for use with the package of FIG.1.

FIG. 7 is a cross-sectional view of the cover of FIG. 6.

FIG. 8 is an exploded view of a package of a second embodiment of thedisclosure.

FIG. 9 is a schematic, cross-sectional view of the assembled package ofFIG. 8.

FIG. 10 is a perspective view of a first container of the package ofFIG. 8.

FIG. 11 is a top view of the first container of FIG. 10.

FIG. 12 is a perspective view of a second container of the package ofFIG. 8.

FIG. 13 is a top view of the second container of FIG. 12.

FIG. 14 is a perspective view a third container of the package of FIG.8.

FIG. 15 is a top view of the third container of FIG. 14.

FIG. 16 is a perspective view of a package of a third embodiment of thedisclosure.

FIG. 17 is an exploded view of the package of FIG. 16.

FIG. 18 is a perspective view of a first container of the package ofFIG. 16.

FIG. 19 is a schematic, top view of the first container of FIG. 18.

FIG. 20 is a schematic, side elevation view of the first container ofFIG. 18.

FIG. 21 is a perspective view of a second container of the package ofFIG. 16.

FIG. 22 is a schematic, top view of the second container of FIG. 21.

FIG. 23 is a schematic, side elevation view of the second container ofFIG. 21.

FIG. 24 is a perspective view of a third container of the package ofFIG. 16.

FIG. 25 is a schematic, top view of the third container of FIG. 24.

FIG. 26 is a schematic, side elevation view of the third container ofFIG. 24.

FIG. 27 is a perspective view of a fourth container of the package ofFIG. 16.

FIG. 28 is a schematic, top view of the fourth container of FIG. 27.

FIG. 29 is a schematic, side elevation view of the fourth container ofFIG. 27.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Exemplary embodiments of this disclosure are described below andillustrated in the accompanying figures, in which like numerals refer tolike parts throughout the several views. The embodiments describedprovide examples and should not be interpreted as limiting the scope ofthe disclosure. Other embodiments, and modifications and improvements ofthe described embodiments, will occur to those skilled in the art andall such other embodiments, modifications and improvements are withinthe scope of the present disclosure.

Referring now in greater detail to the drawings, FIGS. 1 and 2illustrate an apparatus, or more specifically a package 10, that may beused for combined steam and microwave heating of food (not shown) in adomestic microwave oven, in accordance with a first embodiment of thisdisclosure. The package 10 is shown in its fully assembled (e.g.,closed) configuration in FIGS. 1 and 1A, and in an explodedconfiguration in FIG. 2.

The package 10 includes an outer (first) container 12 that, inisolation, is upwardly open and may be in the form of a pressed bowl 12,or the like. The package 10 further includes at least one inner (second)container 14 that, in isolation, is upwardly open and may be at leastpartially in the form of a concentric cylinder. The inner container 14typically has a plurality, or more specifically a multiplicity, of holesor vent openings 40, 42, 44, extending there through. Accordingly, theinner container 14 may be referred to as a basket 14. More generally andin accordance with one aspect of this disclosure, a basket, such as thebasket 14, may be more generally referred to as a container having aplurality and/or multiplicity of holes extending there through, or thelike. In one embodiment, the package 10 further includes a cover 16 thatis shown in FIG. 1 as being transparent or translucent, so that a usermay see through the cover. Alternatively, the cover may be opaque (e.g.,impenetrable by light), or in any other suitable configuration.

The outer container 12 may be formed by pressing and, thus, may bereferred to as a pressed bowl. For example, the outer container 12 maybe a bowl formed by press-forming paperboard that may be coated and/orlaminated with one or more other materials. Alternatively, the bowl 12may be configured/formed in any other suitable manner from any othersuitable materials. The main body of the inner container 14 may becylindrical and may fit concentrically in the bowl 12, although thebasket may be configured differently. The basket 14 may be constructedsimilarly to the bowl 12, or in any other suitable manner. The cover 16may be a flat, thin, flexible, plastic film cover, although the covermay be configured in any other suitable manner.

As shown in FIGS. 1A and 3, the first container 12 is an upwardly openbowl that may has a frustoconical sidewall 18 and an annular flange 20extending outwardly from the upper annular edge of the sidewall. Thebowl 12 typically further includes a disk-shaped bottom wall 22extending inwardly from the lower annular edge of the sidewall, so thatthe bowl is downwardly closed. In one embodiment, the bottom wall 22 andthe sidewall 18 cooperate to form a first interior space 21. As shown inFIGS. 1 A and 3, the sidewall 18 has an indentation or annular lip 38 onthe inner surface of the sidewall spaced below the flange 20. The firstcontainer could be otherwise shaped, arranged, and/or configured withoutdeparting from the disclosure.

As shown in FIGS. 4 and 5, the second container 14 is an upwardly openbasket 14 that has a cylindrical sidewall 24, an annular flange 26extending outwardly from the upper annular edge of the sidewall 24, anda disk-shaped bottom wall 28. The bottom wall 28 extends inwardly froman annular portion of the inner surface of the sidewall 24, wherein thisannular portion of the inner surface of the sidewall 24 is positionedbetween, and distant from each of, the upper and lower annular edges ofthe sidewall 24. That is, the sidewall 24 has a bottom portion 25 thatextends below the bottom wall 28 and contacts the bottom wall 22 of thefirst container 14. As a result, the bottom wall 28 divides the interiorof the basket 14 into upper portion above the bottom wall and a lowerportion below the bottom wall. In one embodiment, a plurality of ventopenings 40 (e.g., perforations or holes) extends through flange 26 ofthe second container 14, a plurality of vent openings 42 extends throughthe sidewall 24, and a plurality of vent openings 44 extends through thebottom wall 28. Each of the vent openings 40, 42, 44 is configured forallowing steam to pass there through, as will be discussed in greaterdetail below.

In the first embodiment, the basket 14 may fit concentrically in thebowl 12, wherein the lower annular edge 27 of the lower portion 25 ofthe second container 14 engages and is supported by the bottom wall 22of the first container 12. Also, the outer annular edge 31 of the flange26 of the second container 14 engages the annular lip or engagingfeature of the sidewall 18 of the first container 12. As such, theheight of the first container 12 is larger than the height of the secondcontainer 14 so that the flange 26 of the second container is spacedbelow the flange 20 of the first container. As a result, when the secondcontainer 14 is installed in the first container 12, a “head-space” isdefined above the basket's flange 26 and the basket's upper chamber.That is, when the basket 14 is positioned in the bowl 12 such that thebasket and bowl are assembled together, the basket's flange 26 extendsin a plane positioned below the bowl's flange 20, so that a gap isdefined between the basket's flange 26 and the cover 16, and thehead-space comprises this gap. In the fully assembled configuration ofthe package 10, the head-space is positioned above, and fully open to,the basket's upper chamber. The head-space is for allowing steam to passtherethrough, as will be discussed in greater detail below.

In the assembled package 10 of one embodiment, the second container 14is received in the firs interior space 21 of the first container 12 sothat the lower annular edge 27 of the sidewall 24 of the basket 14 isengaging and being supported by the bottom wall 22 of the firstcontainer 12. The sidewall 24 and the bottom wall 28 of the secondcontainer 14 cooperate to form a second interior space 33 above thebottom wall that comprises a portion of the first interior space 21.Also, the second container 14 defines a first compartment 35 of thepackage 10 below the bottom wall 28 of the first container and betweenthe lower portion 25 of the annular sidewall 24. A second compartment 37of the package 10 is above the bottom wall 28 and between the portionsof the annular sidewall 24 above the bottom wall 28. In one embodiment,the package comprises a third compartment 39 in the annular spacebetween the sidewalls 24, 18 and below the flange 26. The flange lowerportion of the sidewall 24 engaging the bottom wall 22 of the firstcontainer 12 may form a support structure for supporting the secondcompartment 37 above the first compartment 35. The support structure ofthe basket 14 may be replaced with any other suitable support structure.Also, the flange 26 and the bottom portion 25 of the sidewall 24 arelocating features for locating the second container 14 in the interiorspace 21 of the first container 12.

In the fully assembled configuration of the package 10, an annular sidechamber or third compartment 39 is defined between the sidewalls 18, 24as a result, for example, of these sidewalls having different diameters.The head-space 41 above the flange 26 and the side chamber 39 are areasfor receiving steam and allowing the steam to circulate therein, as willbe discussed in greater detail below.

An example of a method of using the package 10 in accordance with thefirst embodiment is described in the following. In this regard, a sourceof steam is typically placed in the first container 12, so that thesteam source (not shown) is positioned on the bottom wall 22 of thefirst container and located in the first compartment 35 of the package10. The steam source is typically frozen food and/or immobilized highmoisture content food grade material such as, but not limited to, frozenwater (i.e., ice), although other suitable steam sources may be used.

Frozen/refrigerated food (i.e., food product not shown) to be steamed istypically placed in the second compartment of the package 10 so that thefood product is supported on the bottom panel 28 of the second container14. When the basket 14 is positioned in the bowl 12 such that the basketand bowl are assembled together as discussed above, the basket's bottomwall 28, which supports the food to be steamed, is elevated above thebowl's bottom wall 22 and is typically elevated at least slightly abovethe steam source so that enough vertical space is provided between steamsource and the food to be steamed for steam circulation between steamsource and the food to be steamed. While the package 10 is in the fullyassembled (e.g., closed) configuration of FIG. 1, it is configured forallowing for circulation of steam at the bottom, side, and top of thefood to be steamed, for efficient and substantially even steaming of thefood to be steamed. More specifically, the vertical space between steamsource and the food to be steamed, the above-discussed head-space 41,and the above-discussed side chamber 39 are cooperative for allowing forcirculation of steam within the second compartment 37, at the bottom,side, and top of the food to be steamed, for efficient and substantiallyeven steaming of the food to be steamed.

In the fully assembled (e.g., closed) configuration of the package 10shown in FIG. 1, the annular margin of the cover 16 may be fixedly,selectively removably mounted to the bowl's flange 20 for closing (e.g.,hermetically sealing closed) the upper opening of the first container 12and at least partially defining the interior space of the firstcontainer. The cover 16 may be mounted in this location by way ofadhesive material or other suitable fastening features, or morespecifically by a heat seal comprising thermoplastic material. Such afully assembled package 10 may contain contents, such as the steamsource and the food to be steamed in the basket's lower and upperchambers, respectively. In one example, such content-laden, fullyassembled packages 10 may be contained in grocery store freezers, or anyother suitable locations, for being purchased by consumers, although thepackages 10 may be commercialized and/or used in any other suitablemanner

A content-laden, fully assembled package 10 may be placed in a microwaveoven and exposed to microwave energy therein. In response to thecontent-laden, fully assembled package 10 being exposed to the microwaveenergy in the microwave oven, the contents within the package 10 may beheated, such that steam is generated and circulates within the packageas discussed above, and as will be discussed in greater detail below.Preferably (e.g., optionally) the packages include one or more microwaveenergy interactive materials (“MEIMs”) configured for providing rapid,simultaneous microwave and steam cooking in the microwave oven. TheMEIMs may be configured for controlling the heating pattern within thepackage and to control volumetric heating of the food in the package.The MEIMs may include one or more of a susceptor, shield, and/orresonating patch antenna. MEIMs and other features of the package 10 arediscussed in greater detail below, in accordance with the firstembodiment.

Referring back to FIG. 3, MEIM in the form of a frustoconical, uppershield 30 is mounted to, and concentric with, the sidewall 18. The uppershield 30 is configured for deflecting (e.g., reflecting) incidentmicrowave energy in a manner for resulting in a relatively increasedmicrowave energy field at the bottom of the first container 12. Theupper shield 30 is configured for controlling distribution of themicrowave energy, for relatively increasing the amount of microwaveenergy that is directed to/incident upon the stream source located inthe bottom of the first container 12, within the first compartment 35 ofthe package 10. The resulting, relatively high concentration of themicrowave energy field at the bottom of the first container 12 aids infaster heating of steam source. The upper shield 30 may be a MicroRite®shield, or any other suitable MEIM.

Concentrically mounted to the upper surface of the bottom wall 22 isMEIM in the form of at least one lower shield 32. The lower shield 32 isdisk-shaped and has an inner edge 43 defining a central opening. Thelower shield 32 is configured for deflecting (e.g., reflecting) incidentmicrowave energy in a manner for lessening an edge heating effect in amanner that seeks to prevent burning of the material (e.g., paperboard)of the bowl 12 proximate the outer peripheral edge of the bottom wall 22and the lower annular edge of the sidewall 24. The lower shield 32 maybe a MicroRite® shield 32, or any other suitable MEIM.

MEIM in the form of at least one antenna pattern 34 is concentricallypositioned in the central hole of the lower shield 32, and mounted tothe upper surface of the bottom wall 22. The antenna 34 is configuredfor routing at least some of the microwave energy in a manner forresulting in an increased microwave energy field at the bottom of thebowl 12. The antenna 34 is configured for controlling distribution ofthe microwave energy, for increasing the amount of microwave energy thatis directed to/incident upon the stream source located in the bottom ofthe first container 12, within the first compartment 35 of the package10. The resulting, relatively high concentration of the microwave energyfield at the bottom of the bowl 12 aids in faster heating of the steamsource. In one example, the antenna 34 is configured for resonating at,substantially at, and/or approximately at 2450 MHz. The antenna 34 maybe a MicroRite® antenna, or any other suitable MEIM.

MEIM in the form of at least one susceptor 36 is concentricallypositioned in the central hole of the lower shield 32, and mounted tothe portion of the upper surface of the bottom wall 22 at which thelower shield 32 and antenna pattern 34 are not present. The MEIMs 32,34, 36 typically are discontiguous with one another such that gaps areprovided therebetween. The susceptor 36 absorbs microwave energy, andthe susceptor becomes hot and provides heat energy in response itsabsorption of microwave energy. For example, as the susceptor 36 heatsup by absorbing microwave energy, heat energy is conducted from thesusceptor to the steam source that may be in direct contact with, orindirect contact with, the susceptor 36. In addition, the stream sourceis typically further heated by the microwave energy incident upon thestream source. The susceptor 36 may be a MicroRite® susceptor, or anyother suitable MEIM. Typically (e.g., optionally) the MEIMs 30, 32, 34,36 will be positioned between the inner surface of the base material ofthe bowl 12 and a polymeric film of the bowl, or the like, as will bediscussed in greater detail below.

As noted above, in one embodiment, the annular engaging feature 38 (FIG.3), such as a lip, shoulder, groove and/or other suitable feature, maybe defined by or otherwise provided at the bowl's sidewall 18. The outerannular edge 31 of the basket's flange 26 engages against the engagingfeature 38 of the sidewall 18 in the assembled configuration of thepackage 10. This engagement may seek to locate and hold the basket'sflange 26, and thus the basket 14, in its concentric position in thebowl 12, for restricting relative movement between the basket and thebowl in a manner that maintains the above-described head-space.

The engagement between the outer annular edge 31 of the flange 26 andthe engaging feature 38 may be in the form of an interference fit, suchas a relatively loose or a relatively tight interference fit, or it maybe in the form of any other suitable engagement, connection, or thelike. For example, when it is intended for the second container 14 to beremoved from the first container 12, any engagement or connectionbetween the outer annular edge 31 of the flange 26 and the engagingfeature 38 would typically be loose enough to allow a user to readilymanually remove the basket from the bowl. On the other hand,alternatively the outer annular edge 31 of the flange 26 and theengaging feature 38 may be fixedly connected to one another and/or otherfeatures may be provided for restricting removal of the second container14 from the first container 12, such as when the steam source is not afood product and is not intended to be accessed. Irrespective, in thefirst embodiment, the connection (e.g., interference fit) between theouter annular edge 31 of the flange 26 and the engaging feature 38 istypically strong enough so that the package 10 is intended to remain inits fully assembled configuration during shipping, handling and at leastsome of the use of the package 10. In the fully assembled configurationof the package 10, the lower annular edge 27 of the sidewall 24 of thesecond container 14 remains engaged against the bottom wall 22 of thefirst container, and the head-space remains defined above the upperchamber of the basket 14. That is, the connection between the outerannular edge 31 of the flange 26 and the engaging feature 38 seeks torestrict any undesired relative movement between the first container 12and the second container 14 while they are in the assembledconfiguration.

Referring back to FIGS. 1A, 4, and 5, the series of holes 40 extendingthrough the flange 26 are for allowing steam to flow, for example, fromthe side chamber 39, which is defined between the sidewalls 18, 24, tothe head-space 41. The series of holes 42 extending through the sidewall24 are for allowing steam to flow, for example, from the side chamber39, which is defined between the sidewalls 18, 24, to the upper chamber(second compartment) of the package 10. The series of holes 44 extendingthrough the bottom wall 28 of the second container 14 are for allowingsteam to flow, for example, from the first compartment 35 of the package10 to the second compartment 37 of the package.

As schematically illustrated by stippling in FIG. 4, MEIM in the form ofat least one susceptor may be mounted to and carried by the uppersurface of the bottom wall 28 of the second container 14, typicallywithout obstructing the holes 44 in the bottom wall. The one or moresusceptors of the upper surface of the bottom wall 28 absorbs microwaveenergy so as to become hot and provide heat energy to the food to besteamed, which is placed on the bottom wall and located in the secondcompartment 37 of the package. In one example, the food to be steamed isin contact with the susceptor of the bottom wall (e.g., supported by apolymeric film, or the like, of the bottom wall susceptor). As thesusceptor of the bottom wall 28 heats up, at least partial browningand/or frying (e.g., if the bottom wall's susceptor is coated withand/or in contact with oil) is induce at the lower surface of the foodbeing streamed.

The cover 16, which may be a plastic film, is shown in isolation inFIGS. 6 and 7. MEIM in the form of one or more top shields 50 may bemounted to the lower surface of the cover 16, or in any other suitablelocation, like on the upper surface of the cover. The top shields 50 maycomprise one or more patches of aluminum foil, or the like, configuredfor operating as one or more ameliorators. As one example, theameliorator(s) may be formed by etching away portion(s) of the one ormore patches of aluminum foil shielding material mounted to the cover 16to form openings or voids 51 in the aluminum foil. The etching may beperformed at predetermined (e.g., strategic) locations to create thevoids 51 in the top shield 50 for allowing partial transmission ofmicrowave energy through the cover 16 to the food being steamed. Thatis, the ameliorator(s) are configured for controlling penetration ofmicrowave energy (from above) through the cover 16 to the food to besteamed. The partial transmission of the microwave energy provided bythe ameliorator(s) seeks to allow for tempering and thawing of foodbeing steamed, and seeks to allow for balancing of the microwavevolumetric heating effect with the convection-conduction steam heatingeffect. Of course, the thawing feature is present only when the foodbeing steamed is frozen. Reiterating from above, inclusion of theameliorator/top shields 50 may be advantageous because, without it,volumetric heating of the food being steamed through microwave energypenetration may be faster than the convection-conduction heatingprovided by way of the steam. Therefore, to allow sufficient steamingtime, the ameliorating top shields 50 reduce microwave energytransmission from the top thereby balancing with the rate of volumetricheating. In the first embodiment, the ameliorator patches or top shields50 are mostly concentrated at the center of the cover 16 in a mannerthat seeks not to interfere too much with transmission of the microwaveenergy transmission toward the bottom of the bowl 12, wherein thetransmission of the microwave energy toward the bottom of the bowladvantageously seeks to provide for rapid production of steam, asdiscussed in greater detail above. The cover 16 and shields 50 could beotherwise shaped, arranged, and/or configured and the shields 50 couldbe omitted or otherwise configured without departing from thedisclosure.

A second embodiment of this disclosure is like the first embodiment,except for variations noted and variations that will be apparent to oneof ordinary skill in the art. Due to the similarity, components of thesecond embodiment that are identical, similar and/or function in atleast some ways similarly to corresponding components of the firstembodiment have reference numbers incremented by 100.

FIGS. 8 and 9 illustrates an apparatus, or more specifically a package110, that may be used for combined steam and microwave heating of foodin a domestic microwave oven, in accordance with the second embodiment.The package 110 may comprise one or more folded paperboard containers orcartons 112, 114, 160, although these features may be any other suitablestructures.

The package 110 includes an outer (first) container 112 that, inisolation, is upwardly open may be in the form of a box 112. The package110 further includes at least one inner (second) container 114 that, inisolation, is upwardly open. The inner container 114 may be referred toas a lower basket 114. Optionally, the package 110 further includes asecond inner (third) container 160 that, in isolation, is upwardly open.The third container 160 may be referred to as an upper basket 160. Thebaskets 114, 116 may be referred to together as a composite or multipartbasket. The package 110 further includes a cover 116 that is shown inFIG. 14 as being transparent or translucent, so that a user may seethrough the cover. Alternatively, the cover may be opaque (e.g.,impenetrable by light), or in any other suitable configuration.

The first container 112 may be formed by erecting a blank comprisingpaperboard and, thus, may be referred to as a folded carton box;although the box 112 may be formed from any other suitable materialsand/or the box may be constructed/configured in any other suitablemanner. Each of the baskets 114, 160 may also be formed by erecting ablank comprising paperboard, and the baskets may fit concentrically inthe box 112 and with respect to one another in a nested configuration,although the box and baskets may be configured differently. The cover116 may be a flat, thin, flexible, plastic film cover, although thecover may be configured differently.

The first container 112 is shown in isolation in FIGS. 10 and 11. Theupwardly open box 112 may have a frusto-pyramidal assembly of thesidewalls (“sidewall 118”), an assembly of flanges (“flange 120”)extending outwardly from the upper edge of the sidewall, and arectangular bottom wall 122 extending inwardly from the lower edge ofthe sidewall, so that the box is downwardly closed. MEIM in the form ofat least one antenna pattern 134 (FIG. 11) is centrally mounted to theupper surface of the bottom wall 122. The antenna 134 may besubstantially like the antenna 34 discussed above, or this MEIM may bein any other suitable configuration. MEIM in the form of at least onesusceptor 136 is mounted to the portion of the upper surface of thebottom wall 122 at which the antenna pattern 134 is not present, exceptthat the MEIMs 134, 136 are typically discontiguous with one anothersuch that gaps are provided therebetween. The susceptor 136 may besubstantially like the susceptor 36 discussed above, or this MEIM may bein any other suitable configuration. The sidewalls 118 and bottom wall122 cooperate to form a first container space 121. The first container112 could be otherwise shaped, arranged, and/or configured withoutdeparting from the disclosure.

The second container 114 is shown in isolation in FIGS. 12 and 13. Theupwardly open lower basket 114 may have a frusto-pyramidal assembly ofthe sidewalls (“sidewall 124”) that include suspension arms 162connected extending upwardly from opposite portions of the sidewall 124,flanges 126 extending outwardly from upper ends of the suspension arms,flange extensions 164 extending (e.g., upwardly in FIG. 12) from outerends of the flanges 126, and a rectangular bottom wall 128 extendinginwardly from the lower periphery of the sidewall 124. The sidewall 124and the bottom wall 128 of the second container 114 cooperate to form asecond interior space 133. A plurality of vent openings 144 (e.g., holesor perforations) extends through the bottom wall 128 of the lower basket114. Each of the holes 144 in the bottom wall 128 of the lower basket114 are configured for allowing steam to pass therethrough. These holesmay be in a staggered arrangement or may be alternatively arranged.Further, the second container could be otherwise shaped, arranged,and/or configured without departing from the disclosure.

MEIM in the form of a shield 130 extends around the interior of thesecond container 114. The shield 130 is mounted to, and concentric with,the sidewall 124. The shield 130 may be substantially like the shield 30discussed above, or this MEIM may be in any other suitableconfiguration. As schematically illustrated by stippling in FIGS. 12 and13, MEIM in the form of at least one susceptor is mounted to the uppersurface of the bottom wall 128, typically without obstructing the holesin the bottom wall. These one or more susceptors of the bottom wall 128may be substantially like the above-discussed susceptors for the bottomwall 28 of the second container 14 of the first embodiment.

The second container 114 may fit concentrically in the interior space121 of the first container 112 so that the sidewall 124 and bottom wall128 are suspended (e.g., at least partially suspended) by the suspensionarms 162, and the flanges 126 are engaged to (e.g., in opposingface-to-face contact with) and supported by the flange 120 of the firstcontainer 112. The flanges 120, 126 may be connected to one another,such as by way of adhesive material or other suitable fasteningfeatures, or more specifically by heat seals comprising thermoplasticmaterial. As with the first embodiment, the placement of the secondcontainer 114 within the first container 112 creates a first compartment135 of the package 110 that is below the bottom wall 128 of the secondcontainer and a second compartment 137 of the package that is above thebottom wall of the second container. In one embodiment, the side walls124 of the second container 114 may be at least partially inface-to-face contact with the side walls 118 of the first container 112.

The third container 160 is shown in isolation in FIGS. 14 and 15. Theupwardly open upper basket 160 may have a frusto-pyramidal assembly ofthe sidewalls (“sidewall 166”), an assembly of flanges (“flange 168”)extending outwardly from the upper edge of the sidewall 166, and arectangular bottom wall 170 extending inwardly from the lower peripheryfrom the sidewall 166. A plurality of vent openings 181 (e.g., holes orperforations) extends through the bottom wall 170 of the third container160. Each of the openings 181 in the bottom wall 170 of the thirdcontainer 160 is configured for allowing steam to pass therethrough.These holes may be in a staggered arrangement or alternative arranged.The bottom wall 170 and the side walls 166 cooperate to form a thirdinterior space 183 of the third container 160. Further, the thirdcontainer could be otherwise shaped, arranged, and/or configured withoutdeparting from the disclosure.

MEIM in the form of a shield 130 extends around the interior of theupper basket 160. The shield 130 is mounted to, and concentric with, thesidewall 166. The shield 130 may be substantially like the shield 30discussed above, or this MEIM may be in any other suitableconfiguration. As schematically illustrated by stippling in FIGS. 14 and15, MEIM in the form of at least one susceptor is mounted to the uppersurface of the bottom wall 170, typically without obstructing the holesin the bottom wall. These one or more susceptors that are mounted to thebottom wall 170 may be substantially like the above-discussedsusceptors.

The third container 160 may fit concentrically in the box 112 andbetween the suspension arms 162, so that the sidewall 166 and bottomwall 170 are suspended (e.g., at least partially suspended) by theflanges 168, and the flanges 168 are engaged to (e.g., in opposingface-to-face contact with) and supported by the flanges 126 (FIG. 9) ofthe lower basket 114. The flanges 126, 168 may be connected to oneanother, such as by way of adhesive material or other suitable fasteningfeatures, or more specifically by heat seals comprising thermoplasticmaterial. The flange extensions 164 may be folded on top of the flanges168 for increased restraint. The flange extensions 164 and flanges 168may be connected to one another, such as by way of adhesive material orother suitable fastening features, or more specifically by heat sealscomprising thermoplastic material.

Features may be associated with the flanges 120, 126, 168, flangeextensions 164 and/or the connections (e.g., seals) therebetween forallowing these connections to be reasonably easily manually broken orseparated by a user of the package 110. For example, the flanges 120,126, 168, and flange extensions 164 may comprise grooves, an alternatingseries of grooves and/or other features for allowing the subjectconnections (e.g., seals) to be reasonably easily manually broken orotherwise separated, for facilitating at least partial disassembly ofthe package 110. For example, each of the flange extensions 164 of thesecond container 114 is shown as including a hole or gap 172 (FIG. 12)through which a tab 174 (FIG. 14) of the flange 168 extends, wherein thetab 174 is positioned over a hole or gap 176 (FIG. 10) in the flange120.

In the fully assembled (e.g., closed) configuration of the package 110,wherein the second and third containers 114, 160 are nested into thefirst container 112 as discussed above, the package incudes a thirdcompartment 185 above the bottom wall 170 of the third container andbelow the cover 116. The annular margin of the cover 116 may be fixedly,selectively removably mounted to upwardly exposed portions of theflanges 120, 168 and flange extensions 164 for closing (e.g.,hermetically sealing closed) the upper opening of the box 112. The cover116 may be mounted in this location by way of adhesive material or othersuitable fastening features, or more specifically by a heat sealcomprising thermoplastic material. The cover 116 may have MEIM in theform of one or more top shields 150 (FIG. 9) that may be configured tooperate as one or more ameliorators. The top shields 150 may besubstantially like top shields 50 discussed above, having voids oropenings 151 and the ameliorator(s) of the cover 116 may besubstantially like the ameliorator(s) of the cover 16 that are discussedabove, or these MEIMs may be in any other suitable configuration.

Regarding usage of the package 110, a source of steam is typicallyplaced in the first compartment 35 and is supported by the bottom panel122 of the first container 112, so that the steam source is positionedin the bottom of the interior of the package. The steam source may belike that described above for the first embodiment. Frozen/refrigeratedfood to be steamed is typically placed in the second compartment 37supported by the bottom wall 128 of the second container 114 and thethird compartment 185 supported by the bottom wall 170 of the thirdcontainer 160. The package 110 may be characterized as a dual layerpackage for the food to be steamed in that two separate compartments137, 185 can contain food product to be heated by steam and by microwaveenergy. Similar or different types of food can be loaded in therespective compartments 137, 185. When the second and third containers114, 160 are positioned in the first container 112 so that the package110 is assembled as discussed above, the bottom wall 128 of the secondcontainer, which typically supports some of the food to be steamed, iselevated or spaced apart from the bottom wall 122 of the firstcontainer. The bottom wall 128 of the second container 114 is typicallyelevated at least slightly above the steam source so that enoughvertical space is provided between steam source and the food to besteamed for steam circulation between steam source and the food to besteamed. Similarly, the bottom wall 170 of the third container 160,which typically supports some of the food to be steamed, is elevatedabove the bottom wall 128 of the second container 114. The bottom wall170 is typically elevated at least slightly above the food in the secondcompartment 137 so that enough vertical space is provided for steamcirculation.

A third embodiment of this disclosure is like the first and secondembodiments, except for variations noted and variations that will beapparent to one of ordinary skill in the art. Due to the similarity,components of the third embodiment that are identical, similar and/orfunction in at least some ways similarly to corresponding components ofthe first and embodiments have reference numbers incremented by 200 and100, respectively.

FIG. 16 illustrates an apparatus, or more specifically a package 210,that may be used for combined steam and microwave heating of food in adomestic microwave oven, and FIG. 17 shows a portion of the package 210in an exploded configuration, in accordance with the third embodiment.The package 210 may comprise one or more cylindrical features orcontainers 212, 214, 260, 280 which may be arranged in acylinder(s)-within-cylinder arrangement, although these features may beany other suitable structures and may be arranged in any other suitableconfigurations.

The package 210 includes an outer (first) container 212 that, inisolation, is upwardly open and may be in the form of a cylindricalcanister. The package 210 further includes at least one inner (second)container 214 that, in isolation, is upwardly open. The second container214 may be referred to as a basket, or more specifically a lower basket214. Optionally, the package 210 further includes a third inner (fourth)container 280 that, in isolation, is upwardly open. The third container280 may be referred to as an intermediate basket 280. Optionally, thepackage 210 further includes a top (fourth) container 260 that, inisolation, is upwardly open. The containers 214, 260, 280 may bereferred to together as a composite or multipart basket assembly. Thefourth container 260 may be referred to as an upper basket 260. Thepackage 210 further includes a cover 216, similar to the covers 16, 116of the previous embodiments.

The first container 212 is shown in isolation in FIGS. 18-20 andincludes a cylindrical sidewall 218, a circular bottom wall 222extending inwardly from the lower edge of the sidewall so that thecanister is downwardly closed, and an upright, cylindrical flange 282.The flange 282 is coaxial with the sidewall 218 and spaced inwardly fromthe sidewall and typically is fixedly connected to the bottom wall 222.The flange 282 may be configured for being cooperative for interactingwith the lower end of the second container 214 for providing a coaxial,releasable interference fit, or the like, therebetween. In addition, theflange 282 operates as a guide for facilitating coaxial positioning ofthe second container 214 within the interior space 221 of the firstcontainer 212, such that the flange 282 may be referred to as a guide,or the like. More generally, the flange 282 may be referred to as afeature for, or replaced with any other suitable structure for, guidingand/or mounting (e.g., releasably mounting) the second container 214 inthe first container 212, wherein the flange or other suitable structuremay comprise a releasable fastening or interlocking feature forinteracting with the lower portion of the second container 214 forkeeping the basket assembly 214, 260, 280 coaxially in place within thecanister 212. The first container 212 could be otherwise shaped,arranged, configured, and/or omitted without departing from thedisclosure.

MEIM in the form of at least one antenna pattern 234 (FIG. 19) iscentrally mounted to the upper surface of the portion of the bottom wall222 that is substantially circumscribed by the flange 282. The antenna234 may be substantially like the antenna 34 discussed above, or thisMEIM may be in any other suitable configuration. MEIM in the form of atleast one susceptor 236 (FIG. 19) is mounted to the portion of the uppersurface of the bottom wall 222 that is substantially circumscribed bythe flange 282 and at which the antenna pattern 234 is not present,except that the MEIMs 234, 236 are typically discontiguous with oneanother such that gaps are provided therebetween. The susceptor 236 maybe substantially like the susceptor 36 discussed above, or this MEIM maybe in any other suitable configuration.

The second container 214 is shown in isolation in FIGS. 21-23 andcomprises a cylindrical sidewall 224, a disk-shaped bottom wall 228extending inwardly from an annular portion of the inner surface of thesidewall 224, and a coaxial tube or support 284 mounted to and extendingthrough a hole in the bottom wall 228. Regarding the annular portion ofthe inner surface of the sidewall 224 from which the bottom wall 228extends inwardly, this annular portion of the inner surface of thesidewall 224 is positioned between, and distant from each of, the upperand lower annular edges of the sidewall 224. As a result, the bottomwall 228 divides the interior space 233 of the second container 214 intoupper and lower sections or chambers. A plurality of vent openings 242(e.g., holes or perforations) extends the sidewall 224, a plurality ofvent openings 244 extend through the bottom wall 228, and a plurality ofvent openings 245 extend through the support structure or tube 284. Eachof the holes is configured for allowing steam to pass therethrough. Theflange 282 (FIG. 20) of the first container 212 may fit into the lowerchamber of the second container 214, wherein the flange 282 engages therespective portion of the second container 214 in an interference fit,or in any other suitable manner. The second container 214 could beotherwise shaped, arranged, configured, and/or omitted without departingfrom the disclosure.

The upper end of the sidewall 224 and/or support 284, or one or morefeatures associated therewith, may be configured for respectivelyinteracting with the lower ends of the corresponding sidewall andsupport of the third container 280 for guiding and/or releasablymounting the second and third containers 214, 280 together. For example,upright, cylindrical, coaxial flanges 286, 288 may be respectivelyfixedly connected to the upper ends of the sidewall 224 and support tube284 for cooperatively interacting with the lower end of the thirdcontainer 280 and support 291, respectively, for providing a coaxial,releasable interference fits, or the like, therebetween. In addition,the flanges 286, 288 operate as guides for facilitating coaxialpositioning of the second and third containers 214, 280 together andwithin the first container 212, such that the flanges 286, 288 may bereferred to as guides, or the like. More generally, the flanges 286, 288may be referred to as features for, or replaced with any other suitablestructures for, guiding and/or releasably mounting the containers 214,280 together, wherein the flanges 286, 288 or other suitable structuresmay provide or otherwise comprise releasable fastening or interlockingfeatures for keeping at least a portion of the basket assembly 214, 260,280 coaxially in place within the canister 212.

The third container 280 is shown in isolation in FIGS. 24-26 andincludes a cylindrical sidewall 289, a disk-shaped bottom wall 290extending inwardly from an annular portion of the inner surface of thesidewall 289, and a coaxial tube or support 291 mounted to and extendingthrough a hole in the bottom wall 290. Regarding the annular portion ofthe inner surface of the sidewall 289 from which the bottom wall 290extends inwardly, this annular portion of the inner surface of thesidewall 289 is positioned between, and distant from each of, the upperand lower annular edges of the sidewall 289. As a result, the bottomwall 290 divides the interior space 265 of the intermediate basket 280into upper and lower sections or chambers. A plurality of vent openings273 (e.g., perforations or holes) extends through the sidewall 289 ofthe third container 280, a plurality of vent openings 281 extend throughthe bottom wall 290 of the third container, and a plurality of ventopenings 275 extend through the support 291. Each of the holes 273, 275,281 is configured for allowing steam to pass therethrough. The flanges286, 288 (FIG. 21) of the second container 214 may fit into the lowerchamber of the third container 280, wherein the flanges 286, 288respectively engage the lower marginal portions of the sidewall 289 andtube 291 in an interference fit, or in any other suitable manner. Thethird container 280 could be otherwise shaped, arranged, configured,and/or omitted without departing from the disclosure.

The upper end of the sidewall 289 and/or tube 284, or one or morefeatures associated therewith, may be configured for respectivelyinteracting with the lower ends of the corresponding sidewall and tubeof the fourth container 260 for guiding and/or releasably mounting thethird and fourth containers 260, 280 together. For example, upright,cylindrical, coaxial flanges 292, 293 may be respectively fixedlyconnected to the upper ends of the sidewall 289 and tube 291 forcooperatively interacting with the lower end of the fourth container 260and the support 294, respectively, for providing coaxial, releasableinterference fits, or the like, therebetween. In addition, the flanges292, 293 operate as guides for facilitating coaxial positioning of thecontainers 260, 280 together and within the interior space 221 of thefirst container 212, such that the flanges 292, 293 may be referred toas guides, or the like. More generally, the flanges 292, 293 may bereferred to as features for, or replaced with any other suitablestructures for, guiding and/or releasably mounting the containers 260,280 together, wherein the flanges 292, 293 or other suitable structuresmay provide or otherwise comprise releasable fastening or interlockingfeatures for keeping at least a portion of the basket assembly 214, 260,280 coaxially in place within the first containers 212.

The fourth container 260 is shown in isolation in FIGS. 27-29 andcomprises a cylindrical sidewall 266, a disk-shaped bottom wall 270extending inwardly from an annular portion of the inner surface of thesidewall 266, and a coaxial tube or support 294 mounted to and extendingthrough a hole in the bottom wall 270. Regarding the annular portion ofthe inner surface of the sidewall 266 from which the bottom wall 270extends inwardly, this annular portion of the inner surface of thesidewall 266 is positioned between, and distant from each of, the upperand lower annular edges of the sidewall 266. As a result, the bottomwall 270 divides the interior space 277 of the upper basket 260 intoupper and lower sections or chambers. A plurality of vent openings 279(e.g., perforations or holes) extends through the sidewall 266 of thefourth container, a plurality of vent openings 282 extend through thebottom wall 270, and a plurality of vent openings 287 extend through thesupport 294. Each of the holes 279, 282, 287 is configured for allowingsteam to pass therethrough. The flanges 292, 293 (FIG. 24) of the thirdcontainer 280 may fit into the lower chamber of the fourth container260, wherein the flange 292, 293 engage the respective portions of thefourth container 260 in an interference fit, or in any other suitablemanner. The fourth container 260 could be otherwise shaped, arranged,configured, and/or omitted without departing from the disclosure.

In one aspect of the third embodiment, the containers 214, 260, 280 areat least partially releasably interconnected by the support tubes 284,291, 294 and/or the sidewalls 224, 266, 289, such as by way of flanges286, 288, 292, 293 of these features being respectively associated otherportions of these features, such as by way of a releasable interferencefit, or the like. For example, a composite or multipart tube assembly284, 291, 294 may be positioned in the center of the multipart basketassembly 214, 260, 280, and the tube assembly 284, 291, 294 may includeone or more interlocking or other types of fastening features (e.g.,flanges 288, 293) for releasably holding the baskets 214, 260, 280together.

The support tubes 284, 291, 294 each have a plurality of holes extendinglaterally therethrough for allowing penetration and circulation of steamat the center of the basket assembly 214, 260, 280. In the fullyassembled configuration of the package 210, an annular side chamber isdefined between the sidewall 218 of the first container 212 and thesidewalls 224, 266, 289 of the respective containers 214, 280, 260, as aresult, for example, of the outer diameter of the first container 212being larger than the outer diameter of the assembled second, third, andfourth containers 214, 260, 280. This side chamber is an area forreceiving steam and allowing the steam to circulate therein, so thatsteam may circulate through holes 242, 273, 279 in the sidewalls 224,266, 289. The containers 212, 214, 260, 280 may be constructed of rigidpolymer material, paper material, and/or any other suitable materials.Optionally, one or more of the containers 212, 214, 260, 280 may includeMEIM that substantially corresponds to the shields 30, 130 and/orabove-discussed susceptors schematically illustrated in FIGS. 4, 12, 13,14, and 15 by stippling, typically with the MEIM not obstructing theholes in the baskets, although any other suitable MEIM may be utilized.

In the assembled package 210 of the fourth embodiment, the secondcontainer 214 can be located in the first container 212 to create afirst compartment at the bottom of the package similar to the previousembodiments located between the spaced apart bottom panels 228, 222 ofthe respective second container and first container. A source of steamcan be placed in the first compartment of the package. The thirdcontainer 280 can be placed in the first container 212 and in engagementwith the second container 214 so that a second compartment of thepackage 210 is defined between the spaced apart bottom walls 228, 290 ofthe respective second and third containers. The fourth container 260 canbe placed in the first container 212 and in engagement with the thirdcontainer 280 so that a third compartment of the package 210 is definedbetween the spaced apart bottom walls 290, 270 of the respective thirdand fourth containers. The cover 216 can be placed on top of thecontainer 212 so that a fourth compartment of the package 210 is definedbetween the bottom wall 270 of the fourth container 260 and the cover.The package 210 is capable of heating separate food products placed inthe respective second compartments, third compartment, and fourthcompartment by steam that circulates through the package and microwaveheating. The food products in a respective compartment are supported bya respective bottom wall 228, 290, 270 of the second, third, and fourthcontainers 214, 280, 260. The package 210 could be otherwise shaped,arranged, configured, and or used without departing from the disclosure.For example less than three food products could be heated in the package210 without departing from the disclosure. Multiple sources of steamcould be placed in the various compartments of the package 210 withoutdeparting from the disclosure.

Further regarding the above-discussed MEIMs, a susceptor is a thin layerof MEIM that tends to absorb at least a portion of impinging microwaveenergy and convert it to thermal energy (i.e., heat) through resistivelosses in the layer of MEIM. The remainder of the microwave energy iseither reflected by or transmitted through the susceptor. Typicalsusceptors comprise aluminum, generally less than about 500 angstroms inthickness, for example, from about 60 to about 100 angstroms inthickness, and having an optical density of from about 0.15 to about0.35, for example, about 0.17 to about 0.28.

The MEIM may comprise an electroconductive or semiconductive material,for example, a vacuum deposited metal or metal alloy, or a metallic ink,an organic ink, an inorganic ink, a metallic paste, an organic paste, aninorganic paste, or any combination thereof. Examples of metals andmetal alloys that may be suitable include, but are not limited to,aluminum, chromium, copper, inconel alloys (nickel-chromium-molybdenumalloy with niobium), iron, magnesium, nickel, stainless steel, tin,titanium, tungsten, and any combination or alloy thereof.

Alternatively, the MEIM may comprise a metal oxide, for example, oxidesof aluminum, iron, and tin, optionally used in conjunction with anelectrically conductive material. Another metal oxide that may besuitable is indium tin oxide (ITO). ITO has a more uniform crystalstructure and, therefore, is clear at most coating thicknesses.

Alternatively still, the MEIM may comprise a suitable electroconductive,semiconductive, or non-conductive artificial dielectric orferroelectric. Artificial dielectrics comprise conductive, subdividedmaterial in a polymeric or other suitable matrix or binder, and mayinclude flakes of an electroconductive metal, for example, aluminum.

In other embodiments, the MEIM may be carbon-based, for example, asdisclosed in U.S. Pat. Nos. 4,943,456, 5,002,826, 5,118,747, and5,410,135.

In still other embodiments, the MEIM may interact with the magneticportion of the electromagnetic energy in the microwave oven. Correctlychosen materials of this type can self-limit based on the loss ofinteraction when the Curie temperature of the material is reached. Anexample of such an interactive coating is described in U.S. Pat. No.4,283,427.

MEIMs may be combined with films, such as to create microwave susceptorstructures that may be referred to as susceptor films. Susceptor filmmay be laminated or otherwise joined to another material, such as, butnot limited to, a surface of a wall of a package or other suitablestructure. In one example, the susceptor film may be laminated orotherwise joined to paper or paperboard to make a susceptor structurehaving a higher thermal flux output than conventional paper orpaperboard based susceptor structures. The paper may have a basis weightof from about 15 to about 60 lb/ream (lb/3000 sq. ft.), for example,from about 20 to about 40 lb/ream, for example, about 25 lb/ream. Thepaperboard may have a basis weight of from about 60 to about 330lb/ream, for example, from about 80 to about 140 lb/ream. The paperboardgenerally may have a thickness of from about 6 to about 30 mils, forexample, from about 12 to about 28 mils. In one particular example, thepaperboard has a thickness of about 14 mils (0.014 inches). Any suitablepaperboard may be used, for example, a solid bleached sulfate board, forexample, Fortress® board, commercially available from InternationalPaper Company, Memphis, Tenn., or solid unbleached sulfate board, suchas SUS® board, commercially available from Graphic PackagingInternational.

Alternatively, the susceptor film may be laminated or otherwise joinedto another polymer film. It is contemplated that the polymer film wouldexhibit little or no shrinkage, similar to its base film counterpart,such that the performance attributes of the susceptor film are notadversely affected. It is also contemplated that such polymer films maybe clear, translucent, or opaque, as needed for a particularapplication. It is further contemplated that the laminated (or otherwisejoined) structures may be capable of being thermoformable. It isanticipated that shallow draw shapes could preserve susceptorfunctionality in all but the highest stretch areas during thermoforming,and one could advantageously use die and/or plug design to tailor localstretch ratios to customize degree of susceptor functionality. Theinherently lower crystallinity of the films of this disclosure lendthemselves advantageously to formability, as high crystalline materialsdo not form easily, particularly on in-line form-fill-seal packagingmachinery. Post crystallization of formed structures may be inducedthrough methods common to those skilled in the art.

If desired, the susceptor base film may undergo one or more treatmentsto modify the surface prior to depositing the MEIM onto the polymerfilm. By way of example, and not limitation, the polymer film mayundergo a plasma treatment to modify the roughness of the surface of thepolymer film. While not wishing to be bound by theory, it is believedthat such surface treatments may provide a more uniform surface forreceiving the MEIM, which in turn, may increase the heat flux andmaximum temperature of the resulting susceptor structure. Suchtreatments are discussed in U.S. Patent Application Publication No.2010/0213192A1 and U.S. patent application Ser. No. 13/804,673, filedMar. 14, 2013, both of which are incorporated by reference herein in itsentirety.

Also, if desired, the susceptor film may be used in conjunction withother microwave energy interactive elements and/or structures.Structures including multiple susceptor layers are also contemplated. Itwill be appreciated that the use of the present susceptor film and/orstructure with such elements and/or structures may provide enhancedresults as compared with a conventional susceptor.

By way of example, the susceptor film may be used with a foil or highoptical density evaporated material having a thickness sufficient toreflect a substantial portion of impinging microwave energy. Suchelements typically are formed from a conductive, reflective metal ormetal alloy, for example, aluminum, copper, or stainless steel, in theform of a solid patch generally having a thickness of from about0.000285 inches to about 0.005 inches, for example, from about 0.0003inches to about 0.003 inches. Other such elements may have a thicknessof from about 0.00035 inches to about 0.002 inches, for example, 0.0016inches.

In some cases, microwave energy reflecting (or reflective) elements maybe used as shielding elements where the food item is prone to scorchingor drying out during heating. In other cases, smaller microwave energyreflecting elements may be used to diffuse or lessen the intensity ofmicrowave energy. One example of a material utilizing such microwaveenergy reflecting elements is commercially available from GraphicPackaging International, Inc. (Marietta, Ga.) under the trade nameMicroRite® packaging material. In other examples, a plurality ofmicrowave energy reflecting elements may be arranged to form a microwaveenergy distributing element to direct microwave energy to specific areasof the food item. If desired, the loops may be of a length that causesmicrowave energy to resonate (e.g., a resonating patch antenna), therebyenhancing the distribution effect. Examples of microwave energydistributing elements are described in U.S. Pat. Nos. 6,204,492,6,433,322, 6,552,315, and 6,677,563, each of which is incorporated byreference in its entirety.

In still another example, the susceptor film and/or structure may beused with or may be used to form a microwave energy interactiveinsulating material. Examples of such materials are provided in U.S.Pat. No. 7,019,271, U.S. Pat. No. 7,351,942, and U.S. Patent ApplicationPublication No. 2008/0078759 A1, published Apr. 3, 2008, each of whichis incorporated by reference herein in its entirety.

If desired, any of the numerous microwave energy interactive elementsdescribed herein or contemplated hereby may be substantially continuous,that is, without substantial breaks or interruptions, or may bediscontinuous, for example, by including one or more breaks or aperturesthat transmit microwave energy. The breaks or apertures may extendthrough the entire structure, or only through one or more layers. Thenumber, shape, size, and positioning of such breaks or apertures mayvary for a particular application depending on the type of constructbeing formed, the food item to be heated therein or thereon, the desireddegree of heating, browning, and/or crisping, whether direct exposure tomicrowave energy is needed or desired to attain uniform heating of thefood item, the need for regulating the change in temperature of the fooditem through direct heating, and whether and to what extent there is aneed for venting.

By way of illustration, a microwave energy interactive element mayinclude one or more transparent areas to effect dielectric heating ofthe food item. However, where the microwave energy interactive elementcomprises a susceptor, such apertures decrease the total microwaveenergy interactive area, and therefore, decrease the amount of MEIMavailable for heating, browning, and/or crisping the surface of the fooditem. Thus, the relative amounts of microwave energy interactive areasand microwave energy transparent areas must be balanced to attain thedesired overall heating characteristics for the particular food item.

As another example, one or more portions of a susceptor may be designedto be microwave energy inactive to ensure that the microwave energy isfocused efficiently on the areas to be heated, browned, and/or crisped,rather than being lost to portions of the food item not intended to bebrowned and/or crisped or to heating the environment. Additionally oralternatively, it may be beneficial to create one or morediscontinuities or inactive regions to prevent overheating or charringof the food item and/or the construct including the susceptor.

As still another example, a susceptor may incorporate one or more “fuse”elements that limit the propagation of cracks in the susceptor, andthereby control overheating, in areas of the susceptor where heattransfer to the food is low and the susceptor might tend to become toohot. The size and shape of the fuses may be varied as needed. Examplesof susceptors including such fuses are provided, for example, in U.S.Pat. No. 5,412,187, U.S. Pat. No. 5,530,231, U.S. Patent ApplicationPublication No. 2008/0035634A1, published Feb. 14, 2008, and PCTApplication Publication No. WO 2007/127371, published Nov. 8, 2007, eachof which is incorporated by reference herein in its entirety.

It will be noted that any of such discontinuities or apertures in asusceptor may comprise a physical aperture or void in one or more layersor materials used to form the structure or construct, or may be anon-physical “aperture”. A non-physical aperture is a microwave energytransparent area that allows microwave energy to pass through thestructure without an actual void or hole cut through the structure. Suchareas may be formed by simply not applying MEIM to the particular area,by removing MEIM from the particular area, or by mechanicallydeactivating the particular area (rendering the area electricallydiscontinuous). Alternatively, the areas may be formed by chemicallydeactivating the MEIM in the particular area, thereby transforming theMEIM in the area into a substance that is transparent to microwaveenergy (i.e., so that the microwave energy transparent or inactive areacomprises the MEIM in an inactivated condition). While both physical andnon-physical apertures allow the food item to be heated directly by themicrowave energy, a physical aperture also provides a venting functionto allow steam or other vapors or liquid released from the food item tobe carried away from the food item.

In the foregoing, all values, relationships, configurations and otherfeatures may be approximate. For example, the above-described concentricrelationships may be approximate, generally and/or substantiallyconcentric. As another example, the features described above has havinga particular shape (e.g., a cylindrical, frustoconical, annular or diskshape) may be described as approximately, generally and/or substantiallyhaving the subject shape.

The above examples are in no way intended to limit the scope of thepresent disclosure. It will be understood by those skilled in the artthat while the present disclosure has been discussed above withreference to exemplary embodiments, various additions, modifications andchanges can be made thereto without departing from the spirit and scopeof the disclosure as set forth in the claims.

What is claimed is:
 1. A method of heating a food product in a packagein a microwave oven, the method comprising: obtaining a first containerhaving a first sidewall and a first bottom wall, the first sidewall andthe first bottom wall cooperating to form a first interior space;obtaining a second container having a second sidewall and a secondbottom wall, the second sidewall and the second bottom wall cooperatingto form a second interior space, the second bottom wall having at leastone vent opening; positioning the second container in the first interiorspace so that the second interior space comprises a portion of the firstinterior space and the second bottom wall is spaced apart from the firstbottom wall to form a first compartment below the second bottom wall anda second compartment above the second bottom wall; placing a source ofsteam in the first compartment so that the source of steam is supportedby the first bottom wall; placing a food product in the secondcompartment so that the food product is supported by the second bottomwall; and heating the package in a microwave oven so that steam iscreated in the first compartment and circulates to the secondcompartment through the vent openings in the second bottom wall so thatthe food product is heated by the steam and microwave energy.
 2. Themethod of claim 1, wherein the positioning the second container in thefirst interior space comprises engaging a flange of the second containerwith an indentation in the first sidewall to locate the secondcontainer.
 3. The method of claim 1, wherein the positioning the secondcontainer in the first container comprises engaging a flange of thesecond container with a flange of the first container to locate thesecond container.
 4. The method of claim 1, wherein the positioning thesecond container in the first container comprises engaging the secondsidewall with a support on the first bottom wall.
 5. The method of claim1, further comprising obtaining a third container having a thirdsidewall and a third bottom wall, the third sidewall and the thirdbottom wall cooperating to form a third interior space, and positioningthe third container so that the third interior space comprises a portionof the first interior space and the third bottom wall is spaced apartfrom the second bottom wall to at least partially define a thirdcompartment above the third bottom wall.
 6. The method of claim 5,wherein the food product is a first food product, the method furthercomprising placing a second food product in the third compartment. 7.The method of claim 5, further comprising obtaining a fourth containerhaving a fourth sidewall and a fourth bottom wall, the fourth sidewalland the fourth bottom wall cooperating to form a fourth interior space,and positioning the fourth container so that the fourth interior spacecomprises a portion of the first interior space and the fourth bottomwall is spaced apart from the third bottom wall to at least partiallydefine a fourth compartment above the fourth bottom wall.
 8. The methodof claim 7, further comprising placing a third food product in thefourth compartment.
 9. The method of claim 1, wherein the firstcontainer comprises a susceptor on the first bottom wall for absorbingmicrowave energy and wherein the heating the package comprises providingheat from the susceptor to the first product to create steam in thepackage.
 10. The method of claim 9, wherein the first containercomprises an antenna pattern on the first bottom wall, and the heatingthe package comprises directing microwave energy from the first antennapattern to the first product to create steam in the package.
 11. Themethod of claim 1, wherein the second bottom wall comprises microwaveinteractive material and the heating the package comprises heating thefood product by way of the microwave interactive material.
 12. Themethod of claim 1, wherein the first container is an outer container,the first sidewall is an outer sidewall, and the first bottom wall is anouter bottom wall, the second container is an inner container, thesecond side wall is an inner sidewall, and the second bottom wall is aninner bottom wall.
 13. The method of claim 12, wherein the innercontainer comprises a support tube, the support tube being mounted tothe inner bottom wall, wherein the inner sidewall comprises a firstportion extending downwardly from the inner bottom wall toward the outerbottom wall and a second portion extending upwardly from the innerbottom wall.
 14. The method of claim 13, wherein the inner container isa first inner container and the method comprises obtaining a secondinner container and positioning the second inner container in the firstinterior space with the support tube contacting at least a portion ofthe second inner container and at least partially supporting the secondinner container in the first interior space.
 15. The method of claim 14,wherein the first portion of the inner sidewall, the outer bottom wall,and the inner bottom wall at least partially define the firstcompartment, the second portion of the inner sidewall and the innerbottom wall at least partially define the second compartment.
 16. Themethod of claim 15, wherein the inner bottom wall comprises a pluralityof first vent openings for allowing steam to pass from the firstcompartment to the second compartment, and the support tube is in fluidcommunication with the first compartment and comprises a plurality ofsecond vent openings for allowing steam to pass from the firstcompartment to the second compartment via the support tube.
 17. Themethod of claim 16, wherein the support tube extends downwardly from theinner bottom wall in the first compartment and upwardly from the innerbottom wall in the second compartment, the support tube is in fluidcommunication with the second compartment via the plurality of secondvent openings, and the support tube is in fluid communication with thefirst compartment via a plurality of third vent openings.
 18. The methodof claim 17, wherein a side chamber is defined between the outersidewall and the inner sidewall, and the inner sidewall comprises aplurality of third vent openings extending in the first portion and thesecond portion of the inner sidewall for allowing steam to pass from thefirst compartment to the side compartment and from the side compartmentto the second compartment.
 19. The method of claim 17, wherein: theinner sidewall comprises a first inner sidewall, the inner bottom wallcomprises a first inner bottom wall, and the support tube comprises afirst support tube; the second inner container comprises a second innersidewall, a second inner bottom wall, and a second support tube, thesecond support tube being mounted to the second inner bottom wall, thesecond inner sidewall comprising a third portion extending downwardlyfrom the second inner bottom wall toward the outer bottom wall; thefirst inner container comprises a first flange extending upwardly fromthe second portion of the first inner sidewall and a second flangeextending upwardly from the first support tube; and the method comprisespositioning the second inner container with the third portion of thesecond inner sidewall at least partially received by the first flange,and the second support tube at least partially received by the secondflange.
 20. The method of claim 19, wherein the food product is a firstfood product, the second inner sidewall comprises a fourth portionextending upwardly from the second inner bottom wall, the fourth portionof the second inner sidewall and the second inner bottom wall at leastpartially define a third compartment, and the second inner bottom wallcomprises a plurality of third vent openings for allowing steam to passfrom the second compartment to the third compartment, the food productis a first food product, and the method comprises placing a second foodproduct in the third compartment.